Environmental and economic costs of soil erosion and conservation benefits.

Soil erosion is a major environmental threat to the sustainability and productive capacity of agriculture. During the last 40 years, nearly one-third of the world's arable land has been lost by erosion and continues to be lost at a rate of more than 10 million hectares per year. With the addition of a quarter of a million people each day, the world population's food demand is increasing at a time when per capita food productivity is beginning to decline.

Mineralocorticoid excess secondary to adrenal cortical carcinoma.

Adrenal cortical carcinoma may present solely with a syndrome of mineralocorticoid excess. Primary aldosteronism, resulting from adrenal carcinoma, is unusual and has only been reported rarely. A review of the literature revealed 19 cases with marked hypertension and hypokalemia, resulting from mineralocorticoid excess produced by adrenal cortical carcinoma.